Storage tank



7 2 She ets-Sheet l gwomlioaf aizl'fil lik- B. P. MCDANIEL ET AL STORAGE TANK Filed April-6, 1935 Nov; 8, 1938.

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Nov. 8, 1938. B. P. MCDANIEL ET AL STORAGE TANK v Filed April 6, 1935 2 Sheets-Sheet 2 Patented Nov. 8, 1938 UNITED STATES PATENT OFFICE 2,135,724 STORAGE TANK Application April 6, 1935, Serial No. 14,992

6 Claims.

This invention relates to storage tanks for oil,

volatile liquids, and gases, and more particularly to the roof construction for such tanks.

Storage tanks of the type referred to are sealed against vapor losses and it is necessary to provide means for taking care of the physical variations in the accumulated gases in the top of tank due to changes in temperature with the consequent changes in volume or pressure. It is possible to make the tank structure such as to resist any gas pressure changes due to temperature changes but costs for such structures are prohibitive and the more economical design is one which combines provision for changes in volume with a reasonable maximum pressure change. The latter condition may be had by having expansible means which comprises the roof structure in such a manner that the weight of the roof determines the maximum unit pressure allowable and a 0 tendency for higher pressures is counteracted by v movement of the roof proper to increase the sealed volumeof the storage tank.

It is an object of our invention to provide an expansible leak-proof joint of considerable capacity between a storage tank and its roof.

It is a more specific object of our invention to provide an expansible leak-proof joint of a bel-- lows type between a storage tank and its roof in such a manner that changes of sealed volume 0 within the tank due to expanding gases shall be under a predetermined maximum pressure and that such volumetric changes shall be of-considerable amount.

Other objects and advantages will be apparent 3 from the following description, wherein reference is made to the accompanying drawings illustrating the preferred embodiment of our invention.

Fig. 1 is a view in elevation and part section of a storage tank embodying our invention;

) Fig. 2 is a detail section showing a modification I embodying our invention;

Fig. 3 is a detail section showing another modification embodying our invention in its normal collapsed condition; and

i 4 is a detail section showing the relation of parts of the modification shown in Fig. 3 when expanded under pressure of the contained gases.

It is to be understood that the drawings are conventional and diagrammatic in form and that p detail structure ofthe tank is not shown. For instance, it is standard practice, due to the size of the tank, that the body and roof of the tank be made up of a plurality of plates joined together either by riveting or welding, or there may be piping and safety appliances used, but as none of roof I I. In this embodiment of our invention the roof l4 comprises a roof plate I5, a bellows ring IS, a tank roof connecting ring l'l, tank connecting ring l8, and suitable fastening devices I8, 20, 2|, and 22, used to join the contiguous edges of the various parts one to another as shown.

While we prefer rivets, as shown, for fastening devices, any suitable form of fastening device such as bolts or autogenous welding may be used without departing from the spirit or intent of our invention.

Bythe arrangement just described it will be seen that we have provided a form of bellows connection between the roof plate I5 and the tank body I3 by reason of theroof plate I5 being attached to the bellows ring I6, by means of the fastening devices I9, at their outer circumferem tial edges; and by attaching the bellows ring I6- to the tank roof connecting ring, by means of the fastening devices 20, at their inner circumferential edges; and by attaching the tank roof connecting ring at its outer circumferential edge to the tank body I 3' through the medium of the tank connecting ring I8 and the fastening de vices 2i and 22. The joints made by the fastening devices I9-to 22, inclusive, are assumed to be leak-proofcaulking being resorted to if neces-, sary.

The roof plate I5, the bellows ring I6, and the tank roof connecting ring I! are to be made up of standard rolled steel plates suitably joined to- 40 gether in any of the well known methods of riveting, bolting, or welding. The tank connecting ring I8 is preferably made of a standard rolled steel angle section.

In addition to the parts already enumerated we provide also a supporting structure 23 to support the roof II in its normal collapsed position as shown in Fig. 1. This roof supporting structure 23 may be of any suitable design of material, although we prefer to construct it of structural steel.

In Fig. 2 we show a modification of our invention which we use where a greater range of flexibility and variation in volumetric changes are required than can be utilized from the arrangement shown in Fig. 1. The arrangement and function of parts in Fig. 2 is practically identical to that shown in Fig. 1 with the exception that we have added two additional bellows rings. In this embodiment of our invention the roof ll comprises a roof plate 24, an upper bellows ring 25, an-interme'diate bellows ring 26,'a lower bellows ring 21, a tank roof connecting ring 28, a tank connecting ring 29, and a tank' body 30. Suitable fastening devices similar to those shown in Fig. 1 are used to attach the contiguous edges of the various partstogether and need not be enumerated. It will be noted in Fig. 2 that we have arranged the diameter of the various plate members and their rivet circles in such a manner that when the assembled roof is collapsed the rivet circles nest together without interference, and that we preferably maintain the outer diameters of the roof plate 24 and the upper bellows ring 25 greater than that of the underlying rings and for drainage purposes.

In Fig. 3 we show still another modification of our invention. In this arrangement we have the roof plate 3|, an upper bellows ring 32, a lower bellows ring 33, a tank roof connecting ring 34, a tank connecting ring 35, a tank body 36, and a roof supporting structure 31. Suitable fastening devices similar to those described for Figs. 1 and. 2 are similarly'used. It will be noted that in this modification the point of attachment of the roof position taken by the various parts shown in Fig.

3 when under maximum allowable pressure and excess volume, and is illustrative of the action that occurs under similar conditions in the hereinbefore described structures shown in Figs. 1 and 2.

It is obvious that the unit pressure that the roof I willresist before expanding is contingent upon its movable weight, its projected area subject to pressure, and a certain resistance to flexure in the bellows and tank roof connecting rings. We prefer to keep the resistance to flexure low and for this reason we make the bellows ring and the tank roof connecting ring of thinner sheets than the roof plates. It is also obvious that the range of expansion after the weight of the roof has been overcome by the expanding gases is dependent upon the number of bellows rings included in the roof assembly. Therefore, therelative thickness of the plates and the number of bellows rings required will be contingent upon the exigencies of the type of service for which itis designed, and will vary for the same type of tank in different parts of the world.

It is now evident to those skilled in the art that, by the described construction, we;have provided in storage tank roof construction a leakproof expansible joint containing valuable and novel improvements. By utilizing standard rolled steel plates and structural sections we have not only an economical design but one that is efficient from a safety standpoint and is durable.

approved methods of steel plate jointure suchas riveting, bolting, or welding, making it possible to utilize the same method throughout the structure of the entire tank when desirable. The designitself is flexible in that the expansive capacity of a tank may be readily altered after construction by the addition or elimination of bellows rings, this being particularly true where welding is the jointure means.

It will be apparent to those skilled in the art that although we have shown the preferred embodiments of our invention in the hereinbefore described arrangements that still other arrangements could be used without departing from the spirit of our invention.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A storage tank comprising a tank body, a roof supporting structure, a rolled steel plate roof normally sustained by said roof supporting structure, and a metallic bellows connecting leaktight the said tank body to said roof, said metallic bellows comprising a plurality of rolled steel plate rings connected circumferentially alternately at their inner and outer peripheries the said plate rings being unitary in structure and normally in close'stacked relationship with said roof.

2. A storage tank comprising a tank body, a roof supporting structure, a rolled steel plate roof normally sustained by said roof supporting structure, a rolled steel plate ring having its out er circumferential edge attached to the upper peripheral edge of the tank body, and a second rolled steel plate ring interposed between the first mentioned plate ring and the said roof and having its outer circumferential edge attached to said roof and its inner circumferential edge at-, tached to the inner circumferential edge of the first mentioned plate ring, the said plate rings being unitary in structure and normally in close stacked relationship with said roof.

3. A storage tank comprising a tank body, a roof supporting structure, 9. rolled steel plate roof normally sustained by said roof supporting structure, and a plurality of superimposed rolled steel plate rings joined together alternately at their inner and outer circumferential edges and the uppermost plate ring having a circumferential edge joined to the roof and the lowermost plate ring having a circumferential edge joinedv .to the upper peripheral edge of the tank body,

the said plate rings being unitary in structure and normally in close stacked relationship with said roof.

4. Astorage tank, comprising a tank body, a roof supporting structure, a rolled steel plate roof normally sustained by said roof supporting structure, and a plurality of superimposed rolled steel plate rings joined together alternately at their inner and outer circumferential edges and the uppermost plate ring having a circumferential edge joined to the roof and the lowermost plate ring having its outer circumferential edge joined to the upper peripheral edge of the tank body, the said plate rings being unitary in structure and normally in close stacked relationship with said roof.

5. A storage tank for volatile liquids comprising a rigid tank body 'for holding the liquid, a steel roof for the tank; a metallic bellows fixed at its lower periphery to said tank body and fixed at its upper periphery to said roof, saidmetallic bellows comprising a plurality of rolled steel plate rings connected circumferentially alternately at their inner and outer peripheries, and means located within said rigid tank body for supporting the weight of the roof. and bellows when said bellows is in the collapsed condition.

6. In a storage tank for volatileliquids. an expansion roof therefor comprising an outer ring portion secured around the outer periphery thereof to the wall or the tank. a central plate portion, and means securing the central plate portion to said outer ring portion to permit the central plate portion to move upwardly upon abnormal pressure in the tank to thereby increase the vapor space in the tank, said means including a plurality of intermediate overlapping rings and which slope in opposite directions as regards ad- 'jacent rings when the roof is expanded, the inside diameter of certain intermediate rings progressively decreasing in an upward direction to render the Joints thereof accessible for repair, and supporting structure in'the tank for sustaining the roof in a substantially horizontal plane when normal pressure exists within the tank.

BRUCE P. MODANIEL. HIR-AM E. GINGRICH. 

